<?php

abstract class aDB{

/*

*连接数据库，从配置文件读取配置信息

*/

abstract public function conn();

abstract public function query();

// abstract public function getAll();

}

class Mysql extends aDB{

public $link;

/*

*连接数据库，从配置文件读取配置信息

*/

public function conn(){

include 'config.php';

$this->link = new mysqli($cfg['host'], $cfg['user'], $cfg['pwd'], $cfg['db']);

var_dump($this->link);

}

public function query($sql){

return $this->link->query($sql);

}

// public function getAll($sql){

// $res = $this->query($sql);

// var_dump($res);

// }

} 

$mysql = new Mysql();

$mysql->conn();

?>